Added lots of tests from Lib SelfTest.cs to Test project

Code cleanup in KeePassLib
Code cleanup in ModernKeePass.Tests
Argon2Kdf files can now be opened
WIP - Argon2kdf files are corrupted on write

ModernKeePassLib.Test/Cryptography/CryptoRandomTests.cs

@@ -7,7 +7,7 @@ using KeePassLib.Cryptography;
 using ModernKeePassLib.Cryptography;
 #endif
 
-namespace ModernKeePassLib.Test.Shared.Cryptography
+namespace ModernKeePassLib.Test.Cryptography
 {
   [TestFixture ()]
   public class CryptoRandomTests